( Reaffirmed 2003 ) IS : 8862 - 1978 Indian Standard SPECIFICATION FOR TITANIUM DIOXIDE ( ANATASE FOR RUBBER INDUSTRY Rubber Chairman DR D. BANERJEE Members Ministry of Defence ( R & D ) SRRI M. L. BAHRANI SERI ANIL .~GARWAL ( Alternate ) Ministry of Defence ( DGI ) SHRI A. K. BANDYOPADHAYA SHRI M. KUMARAN ( Alternate ) Directorate SHRI A. T. BASAK General of Supplies & Disposals, New Delhi National Test House, Calcutta SHRI S. K. BOSE SHRI A GHOSH ( Altcrnats) Bayer (India ) Ltd, Bombay DR S. N. CHAKRAVARTY SHRI R. R. PANDIT ( Alternate ) Alkali & Chemical Corporation of India Ltd, SHRI D. K. CHATTERJEE Rishra DR S. K. ROY ( Alternate ) Export Inspection Council of India, Calcutta SHRI 0. P. DHAMIJA \ SHRI P. K. CHATTERJEE ( Alternate 1 Indian Petrochemicals Corporation Ltd, JawaharSHRI K. N. GANESH nagar Dunlop India Ltd, Calcutta SHRI S. B. GAN~ULI SHRI P. N. S. MYER ( Alternate ) Madras Rubber Factory Ltd, Madras SHRI A. GEOROE JOHN SHRI K. J. ABRAHAM ( Alternate 1 Cosmos India Rubber Works Pvt Ltd, Bombay SHRI LALIT MOHAN JAMNADAS SHRI PULIN L. KINARIWALA ( Alternate ) Indian foil Corporation Ltd, Bombay `&I&I R. C. JHINOAN SHRI M. K. JAIN ( Alternate ) National Rubber Manufacturers' Ltd, Calcutta DR I. V. KRISHNAMURTI SHRI J. CWATTERJEE ( Altmafe ) Lathia Rubber Manufacturing Co Pvt Ltd, Bombay SHRI S. V. LATHIA SHRI D. P. LATHIA ( Alternate ) All India Rubber Industries Association, Bombay SHRI V. N. MAKER SHBI M. M. PATEL ( Alternate ) ( Continued on page 2 ) @ Copyright STANDARDS 1978 INSTITUTION TYPE ) Products Sectional Committee, Representing PCDC 13 Escon Consultants Pvt Ltd, Calcutta INDIAN This publication is protected under the Indian CopFight Act ( XIV of 1957 ) and reproduction in whole or in part by any means except with written permission of the publisher shall be deemed to be an infringement of copyright under the said Act. IS : 8862 - 1978 ( Continued from page 1 ) Members DR S. P. MANIK SHRI D. N. V. CRELLAM Dn W. MILINS Railway Representing Board, Ministry of Railways Indian Rubber Manufacturers' Research Association, Bombay Rubber Board, Kottayam DR C. K. N. NAIR Sundaram Industies Pvt Ltd, Madras SHRI N. NAOARAJAN SHRI P. VIJAYARAGHAVAN ( Alternate ) Bata India Ltd, Calcutta SERI S. C. NANDY SRRI SUNIL SARKAR (Alternate ) Directorate General of Technical Development, DR N. V. C. RAO New Delhi SHRI G. R. INAMDAR (Alternate ) Director %eneral, ISI ( Ex-oficio Member ) SHRI M. S. SAXENA, Director ( P & C ) Secretary SHRI SATISH CHANDER Deputy Director ( P & C ), IS1 ( Alternate) Rubber Conoener Chemicals & Compounding Ingredients Subcommittee, PCDC 13 : 5 Escon Consultants Pvt Ltd, Calcutta Snnr A. K. SEN CIIAUDHURI Members Bayer ( India ) Ltd, Bombay DR M. C. BADRINARAYANA DR S. N. CKAKRAVARTY ( Alternate ) Ministry of Defence ( DGI ) SHEI A. K. BANDY~PADHYA SnRI P. L. Naa ( Alternate ) Indian Rubber Manufacturers' Research Association, SHRI B. BANERJEE Bombay Inchek Tyres Ltd, Calcutta Snnr B. BHATTACHARYA SHRI P. K. SARKAR ( filternate) National Test House, Calcutta SHRI S. K. Boar: DR D. K. DAS ( Alternate ) Alkali & Chemical Corporation of India Ltd, SHRI D. K. CHATTERJEE Rishra DR S. K. RAY ( Alternate ) National Rubber Manufacturers Ltd, Calcutta SHRI J. CRATTERJEE SHRI A. K. BISWAS ( Allenrate ) United Carbon Yndia Ltd, Bombay SHRI R. W. DRARWADKAR Dunlop India Ltd, Calcutta SHRI S. B. GANQULI SHRI A. SEN ( Alternate ) All India Rubber Industries Association, Bombay; DR A. S. GHAQ and Mindia Chemicals Ltd, Bombay SHRI S. V. LATHIA ( Alternate ) All India Rubber Industries Association, Bombay Mindia Chemicals Ltd, Bombay SHRI H. B. KINOSLEY ( Alternate ) ( Continued on page 14 ) L 2 IS :8862- 1978 Indian Standard SPECIFICATION FOR TITANIUM DIOXIDE ( ANATASE FOR RUBBER INDUSTRY TYPE ) 0. 0.1 This Indian FOREWORD Standard was adopted by the Indian Standards Institution on 10 July 1978, after the draft finalized by the Rubber Products Sectional Committee had been approved by the Petroleum, Coal and Related Products Division Council. 0.2 Titanium dioxide, anatase, one of the two crystalline forms of titanium dioxide is used in the rubber industry as a white pigment for the manufacture of white and light coloured rubber products. The distinction between the two forms, namely rutile and anatase can be done by X-ray crystallography. The same has, however not been included in the specification as the facilities for doing this test are not widely available. 0.3 In reporting the result of a test or analysis made in accordance with this standard, if the final value observed or calculated is to be rounded off, it shall be done in accordance with IS : 2-1960*. 1. SCOPE 1.1 This standard prescribes the requirements and methods of sampling and test for titanium dioxide ( anatase type ) in powder form intended for use as a white pigment in rubber compounds. 2. REQUIREMENTS powder, 2.1 Appearance - The free from lumps, material shall be in the form grit and extraneous matter. of a white fine 1 2.2 The material shall comply with the requirements given in Table when tested according to the methods listed in co1 4 of the table. *Rules for rounding off numerical values ( revised ). 3 IS : 8862 - 1978 TABLE 1 REQUIREMENTS OF TITANIUM DIOXIDE FOR RUBBER INDUSTRY ( Clauses 2.2, 4.2 and4.3 SL No. (1) i) ii) Colour percent Sieve residue, by mass, Max: a) b) Through IS Sieve Through IS Sieve 158 micron 45 micron 0.01 0.05 3'85-3.95 6 to 8 percent 0'5 0.5 98.0 4 of IS 5 of IS 7 of IS 8 of IS CHARACTERISTIO (2) REQUIREMENT (3) Close match to the approved sample ( ANATASE TYPE ) ) METHOD OF TEST, REF TO (4) Visual Examination 3 of IS : 7086 ( Part I )-1973* iii) iv) v) vi) vii) viii) ix) x) Rel;ltz density at 27'C/ : 7086 ( Part I )-1973f : 7086 ( Part I )-1973* : 7086 ( Part I )-1973* : 7086 ( Part I )-1973' Appendix A pH Moisture content, by mass, Max Matter soluble in water, percent by mass, Max Titanium dioxide percent TiCs ), mass, Min ( as by Copper, percent by mass, Max Iron, percent by mass, Max Solubility in ;$ure of and sulphuric ' ammonium sulphate *Methods of sampling 0'002 0.04 To pass the test Appendix Appendix Appendix B C D and test for rubber compounding ingredients, Part I. 3. PACKING 3.1 Packing purchaser AND MARKING shall be packed as agreed closed between and if any; the - The material and the supplier. 3.2 Marking - Each package marked to furnish the following shall be securely information: and registered legibly a>Manufacturer's b) cl 4 Name Lot, batch name trade-mark, and of the material; in the package; number and year of manufacture. 4 Net mass of the material IS : 8862 - 1978 Mark. 3.2.1 Each package may also be marked with the ISI Certification NOTE - The use of the IS1 Certification Mark is governed by the provisions of the Indian Standards Institution ( Certification Marks ) Act and the Rules and Regulations made thereunder. The IS1 mark on products covered by an Indian Standard conveys the assurance that they have been produced to comply with the requirements of that standard under a well-defined system of inspection, testing and quality control which is devised and supervised by IS1 and operated by the producer. IS1 marked products are also continuously checked by IS1 for conformity to that standard as a further safeDetails of conditions under which a licence for the use of the IS1 Certification guard. Mark may be granted to manufacturers or processors, may be obtained from the Indian Standards Institution. 4. SAMPLING AND CRITERIA FOR CONFORMITY shall be done as prescribed in 15 of 4.1 Sampling - The sampling IS : 7086 ( Part I )-1973*. 4.2 Number of Tests - Tests for all the characteristics shall be conducted on a composite sample. 4.3 Criteria for Conformity conforming to the specification, the requirements given in Table - The lot shall if the composite 1. ( see Table 1) as all be considered sample satisfies APPENDIX [ Table I, Sl No. DETERMINATION A-O. GENERAL A (vii) ] OF TITANIUM DIOXIDE for the determination of titanium dioxide For routine testing, either Method 1 or Method prescribed. followed but in case of dispute, Method 1 shall be applicable. A-1. A-0.1 Two methods have been 2 may be METHOD 1 ZINC REDUCTION METHOD A-l.0 Outline of the Method - A solution of the dry pigment is made with concentrated sulphuric acid and ammonium sulphate. Titanium is reduced with zinc amalgam in Nakazono reductor and the resulting trivalent titanium is titrated with ferric alum. *Methods of sampling and test for rubber compounding ingredients, Part I. 5 IS : 8862 - 1978 A-I.1 Apparatus A-1.1.1 .Nakazono Reductor - The apparatus as shown in Fig. 1, consists of a bulb A with a capacity of 500 ml with three stopcocks B, C and D attached. To the stopcock D may be attached, by means of thick rubber tubing E, a small cylindrical flask F of about 50 ml capacity. The stopccck C which is smaller in bore than either of the other two serves to admit carbon dioxide or nitrogen. Ail dimensions in millimetres. FIG. 1 NAKAZONO REDUCTOR 6 IS:8862 - 1978 A-l.2 Reagents A-l .2.1 Concentrated Sulphuric Acid 1961* ). relative density 1.84 ( see IS : 266- A-1.2.2 Ammonium Sulphate A-1.2.3 zinc Amalgam 3 percent, prepared as given below: Place 50 ml of mercury in a small porcelain dish on a hot water-bath, covering the surface of the mercury with 2 percent ( m/u ) sulphuric acid. Add about 25 g of zinc in small granules. Stir from time to time and replenish the dilute acid with water as required. When all the zinc has disappeared, allow the amalgam to cool and stand for several hours. Finally filter through a Gooch crucible with no asbestos pad. Store the amalgam in glass bottle under 2 percent ( m/v ) sulphuric acid. A-1.2.4 follows: Standard Ferric Alum Solution 0.062 5 N, standardized as Transfer by a pipette 50 ml of the ferric alum solution to be standardized to the Nakazono reductor prepared ready for use as Displace the air in the reductor by described in A-1.3.2. passing carbon dioxide for 3 minutes. Close the taps B and C. Bring the amalgam into intimate contact with ferric alum solution by shaking the apparatus vigorously for 5 minutes. Place the Drain the amalgam and pass inert gas apparatus on a ring stand. as described under A-1.3.4. Titrate it against standard potassium permanganate. The end point is the appearance of light pink colour at least persistent for 30 seconds. Calculate the strength of the ferric alum solution as follows: 0'1 v X 50 Strength where of ferric alum solution - V = volume solution of 0.1 required N standard for titration. Solution - potassium permanganate A-1.2.5 Potassium *Specification Thiocyanate 10 percent ( m/v ). for sulphuric acid ( reuized ). 7 IS : 8862 - 1978 A-l.3 Procedure A-1.3.1 Weigh approximately 0.5 g of the dried material to the nearest 0.1 mg, into a 250-ml beaker. Add 20 ml of concentrated sulphuric acid and 10 g of ammonium sulphate. Mix carefully and heat on a hot plate to fuming and then over a strong flame until solution is observing caution while examining the solution. complete, Cool the solution, dilute with 100 ml of distilled water, stir and filter, if necessary. A-1.3.2 Open stopcock C, transfer sufficient quantity of 4 percent sulphuric acid to fill the bottom flask and leave no air space below the stopcock D. Close tap D and add 20 ml of zinc amalgam to A. The reductor is now ready for use. A-1.3.3 To the amal-gam contained in A, transfer the solution, warmed to 5O"C, which shall not exceed 300 ml in volume. Then pass carbon dioxide or nitrogen for about 3 minutes. Close taps B and C and simultaneously disconnect the carbon dioxide supply. Bring the amalgam into intimate contact with the solution by shaking the apparatus vigorously for 5 minutes, holding it in such a way that the stopcocks are kept shut and in position. The rate of reduction is apparent by development of the characteristic violet colour of the trivalent titanium. Place the apparatus on a ring stand. Open stocpcock D and allow the amalgam to flow slowly into F. Close D immediately as soon as the amalgam has been completely transferred. With taps B and D open, pass inert gas through D as before, add IO ml solution and titrate with standard ferric alum potassium thiocyanate solution until a faint pink coloration persists for one minute. A-1.3.4 slightly A-1.3.5 extension A-4.4 glass tubing Facilitate the titration by attaching a piece of very narrow to the tip of the burette-with a piece of rubber tubing. The passes through stopcock B into the bulb A. Calculation dioxide content, by mass v. x 0.005 M Titanium percent where V = = X 100 volume and in ml of 0.062 5 N ferric taken. alum solution required, M = mass in g of pigment 8 IS : 8862 - 1978 A-2. METHOD 2 ALUMINIUM REDUCTION METHOD A-2.0 Outline of the Method - This method is similar to zinc Titanium is reduction method but easier and quicker to operate. reduced to trivalent state by aluminium and titrated against ferric ammonium sulphate using ammonium thiocyanate as indicator. A-2.1 Apparatus A-2.1.1 Delivery Tube - made of about 4 mm internal diameter glass tube, bent in such a way as to have a horizontal run of about 150 mm and vertical drop of about 75 mm at one end, and a vertical drop of about 150 mm at the other end. A-2.1.2 A-2.2 Long Necked Flask 500-ml capacity. Reagents Ammonium Sulphuric Sulfihate Acid relative density 1'84 ( see IS : 266-1961* ). ). A-2.2.1 A-2.2.2 A-2.2.3 A-2.2.Q A-2.2.!i A-2.2.6 Hydrochloric Acid - relative electrolytic Solution - density grade. 1'19 ( see IS : 265-19627 Aluminium Foil Sodium Bicarbonate Ammonium saturated. Solution prepared as follows: Thiocyanate Indicator Dissolve 24'5 g of ammonium thiocyanate in 80 ml of hot water. Filter, cool to room temperature, dilute to 100 ml and preserve in well stoppered, amber coloured bottle. A-2.2.7 follows: Standard Ferric Ammonium Sulphate Solution prepared as Dissolve 30.16 g of fresh ferric ammonium sulphate 15 ml [ FeNHs(S04)z, 12 H20 1 in 800 ml of water containing of concentrated sulphuric acid. Add 0.1 N potassium permanganate solution until a very slight pink colour is obtained. Dilute to 1000 ml and mix thoroughly. Filter, if necessary. Standardize with 0.190 0 to 0.210 0 g of standard titanium dioxide of known purity prescribed in A-2.3 and calculate titanium dioxide equivalent of solution in grams of titanium dioxide per millilitre of solution as given below: Titanium *Specification @pccibication dioxide equivalent -= VMXxlo', for sulphuric acid ( revised ). for hydrochloric acid ( revised ). 9 IS : 8862 - I978 where M = mass in g of standard P = percentage dioxide titanium dixoide taken for test, titanium solution of titanium used, and in ml of ferric for titration. dioxide in standard sulphate V = volume A-2.3 Procedure required ammonium A-2.3.1 Weigh accurately about 0'190 0 to 0.210 0 g of the dry material and transfer the same to a 500-ml long necked flask. Add 7 to 9 g of ammonium sulphate and 20 ml of sulphuric acid, mix carefully, heat on a hot plate to fuming and then over a strong flame until solution is complete. Cool and add 120 ml of water and 20 ml of hydrochloric acid. Boil the contents and remove from heat. A-2.3.2 Insert the short end of the delivery tube into one hole of a two-hole rubber stopper suitable for the long necked flask. Insert a glass rod with a hook at the bottom end in the other hole in such a way that the bottom end shall be nearer to the bottom of the flask when the stopper is fitted into the flask. Attach nearly 1 g of aluminium foil to the bottom end of the rod by coiling it around the rod. Insert the stopper, carrying the rod with foil and delivery tube, into the flask in such a way that the foil is near the bottom of the flask at the same time that the long end of the delivery tube is near the bottom of a 250-ml beaker containing about 150-ml of sodium bicarbonate solution. A-2.3.3 complete assembly. sodium carbon stopper, rinsings solution sulphate A-2.4 Heat the flask as soon as the dissolution of aluminium is to gentle boiling for 3 to 5 minutes without disturbing the Cool to 60°C by partial immersion in water and siphon the bicarbonate solution into the flask giving an atmosphere of dioxide over the reduced titanium solution. Withdraw the rinse the glass rod attached to it with a little water catching the Add 2 ml of ammonium thiocyanate indicator in the flask. and titrate immediately against standard ferric ammonium solution to a straw coloured end point. Titanium percent where ~dioxide, by mass Calculation = Vx E x 100 M sulphate solution ) of used ferric V = volume in ml of ferric in test, ammonium E = titanium ammonium dioxide equivalent ( see A-2.2.7 sulphate solution in g/ml, and taken for test. 10 M = mass in g of material IS : 8862 -1978 APPENDIX B [ Table 1, SZ.No. (viii) ] DETERMINATION B-l. REAGENTS OF COPPER B-l.1 Standard Copper Sulphate Solution - Weigh 0'393 0 g of copper sulphate ( CuS04.5H@ ) into a small beaker and dissolve in Cautiously add 5 ml of concentrated sulphuric acid ( relative water. Dilute to the density I.84 ) and transfer to a 1 000 ml volumetric flask. mark and shake to ensure homogeneity. Pipette 10 ml of this solution into a loo-ml volumetric flask, dilute to the mark with water and mix. Each millilitre of the final solution contains 0'000 01 g copper ( as Cu ). B-1.2 Concentrated (see IS : 265-1962* ). B-l.3 Nitric Acid Hydrochloric relative density Acid Relative density ). l-19 1'40 ( see IS : 264-19687 10 g of citric B-l.4 Citric water. B-l.5 Acid Solution Hydroxide Dissolve Solution acid in 100 ml of Ammonium B-l.6 Sodium Diethyldithiocarbamate gum tragacanth with about 1 ml of boiling water. When cool, dissolve diethyldithiocarbamate. B-2. PROCEDURE - Moisten about 0.01 g of acetone and pour into 1 litre of in this solution 1 g of sodium B-2.1 Weigh 5 g of the sample, accurately weighed, into a 200-ml beaker, add 200 ml of concentrated hydrochloric acid and 4 ml of concentrated nitric acid. Cover with glass and heat for one hour with occasional stirring. Dilute to 40 ml with water and add 10 ml of citric acid solution followed by ammonium hydroxide, added dropwise, until the solution is just alkaline to litmus and then 2 ml in excess. Bring to boil and allow to stand for 15 to 20 minutes in warm place. Filter into a lOO-ml Nessler cylinder, wash with distilled water until the volume of the filtrate is 70 to 80 ml. Add 10 ml of sodium diethyldithiocarbamate solution and make up to 100 ml with distilled water. B-2.2 Prepare a blank solution from the same diluted to 100 ml in a second Nessler cylinder. *Specification tspecification for hydrochloric acid ( rcuised). for nitric acid ( first rcuision ). quantities of reagents 11 IS:8862 -1978 B-2.3 By means of a burette add standard copper sulphate solution to the blank, and equal volumes of water to the sample solution until the colour intensities in the two cylinders are identical. Note the volume of copper solution required. B-3. B-3.1 CALCULATION Calculate the copper content as follows: I' )i O*OOl =--_---- Copper content, by mass where V = volume percent M copper solution required, and in ml of standard M = mass in g of the sample taken. APPENDIX C [ Table 1, Sl JVO. (ix) ] DETERMINATION C-l. C-l.1 REAGENTS Dilute Hydrochloric ). Persulphate solid. Acid approximately Acid 0.2 N. density 1.19 OF IRON C-1.2 Concentrated ( see IS : 265-1962* C-1.3 Ammonium Hydrochloric relative C-1.4 Butanolic Potassium Thiocyanate - Dissolve about 10 g of potassium thiocyanate in 10 ml of water at 27 f 2°C. Add n-butyl alcohol to make up to 100 ml and shake vigorously until the solution is clear. G-I.5 Dilute SulphurZc Acid 10 percent ( u/v ). 0.702 g of ammonium G-I.6 Standard Iron Solution - Dissolve ferrous sulphate [ (NH4)2SOIr.FeSO,.GH~O ] in 20 ml of water containing 5 ml of concentrated sulphuric acid and dilute with water One millilitre of the solution contains 0.1 mg of iron to 1000 ml. (as Fe). *Specification for hydrochloric acid (-rrvised ). 12 IS : 8862 - 1978 C-2. PROCEDURE C-2.1 Take approximately 5 g of moisture free sample of titanium dioxide weighed accurately to O-001 g in a 400-ml beaker and boil with 20 ml of dilute hydrochloric acid, till a little acid ( approximately 5mml) is left. Further add 15 ml of concentrated hydrochloric acid and slowly boil till some acid is left as before. Add 20 ml of distilled water Filter hot through a filter paper ( Whatman and boil for 5 minutes. If the No. 42 or equivalent ) collecting the filtrate in a 400-ml beaker. filtrate appear turbid, filter again through the same filter paper, collecting the filtrate in another 400-ml beaker. Wash the residue in filter paper several times with hot water, till a drop of washing is neutral to Evaporate the total filtrate to less than 75 ml, cool blue litmus paper. to room temperature and transfer to a loo-ml volumetric flask. Wash the beaker and transfer the washings to loo-ml flask and make up the volume. C-2.2 Take 20 ml of the solution from the volumetric flask in a Nessler cylinder. Add 30 mg of ammonium persulphate and 15 ml of butanolic potassium thiocyanate and make up to 50 ml. Shake vigorously for 30 seconds and allow the liquids to separate. Carry out a control test in the second Nessler cylinder using 4 ml of standard iron solution and the same quantities of other reagents in the same volume of the Match the colour produced in the butanol layers reaction mixture. after 2 minutes. C-2.3 The limit prescribed shall be taken the intensity of colour with the sample control test. to have not been exceeded if is not greater than that in the APPENDIX D [ l-able 1, 5'2No. (x) ] SOLUBILITY IN MIXTURE AND AMMONIUM D-l. PROCEDURE OF SU'3vPHURIC SULPHATE ACID D-l.1 Dissolve O-2 g of the titanium dioxide in a mixture of 25 ml of concentrated sulphuric acid and 10 g of ammonium sulphate. Add a few drops of hydrogen peroxide. Deep orange colour should develop. 13 IS : 8862 - 1978 ( Continued from page 2 ) SHRI Rcpresen t ing Members Pturdia Chemicals Ltd, Bombay J. N. GHOSA;L SHRI H. C. VIJAYANATH ( Alternate ) Cosmos India Rubber Works Pvt Ltd, Bombay SHRI C. S. INAMDAR SHRI SEN GUPTA ( Alternate ) Camphor & Allied Products Ltd, Bareilly SHRI S. M. MEHTA SWRI S. N. MEHRA ( Alternate ) Bata India Ltd, Calcutta SHRI S. C. NANDY SHRI S. SARKAR ( Ahrnntc ) Travancore Titanium Products Ltd, Trivandrum DR V. S. VIJAYAN NAYAR Synthetics & Chemicals Ltd, Bombay SHRI M. M. PATEL SHRI R. P. DUBEY ( Alt.-mate) Swastik Rubber Products Ltd, Pune SHRI V. D. PENDSE SHRI S. V. TATHAWADKAR ( Alternate ) I. A. & I. C. Pvt Ltd, Bombay SHRI P. S. PRATAP SHRI C. N. VYAS ( Alternate ) Philips Carbon Black Ltd, Calcutta SHRI R. ROY CHOWDHURY Canara Rubber Products Pvt Ltd, Mangalore DR S. M. SHETTY Waldies Limited, Calcutta SHRI D. V. WITTENBAKER SHBI A. DEB ( Altcrnate ) 14